Mohammed el-Baradei, head of the International Atomic Energy Agency, and UN chief weapons inspector Hans Blix, emerging from talks with the prime minister and Jack Straw at Downing Street, said Iraq had to show "drastic change".

Saddam Hussein's regime needed to show progress by the time the inspectors produce their next report to the UN on February 14, Mr el-Baradei said.

Mr el-Baradei said: "I think the message coming from the security council is very clear: that Iraq is not cooperating fully, that they need to show drastic change in terms of cooperation.

"The message also coming from the security council is that time is very critical, and that we need to show progress in our report due on the 14th of this month.

"So our mission, I think, in Baghdad this weekend is crucial and we hope we will secure full 100% cooperation on the part of Iraq."

Mr el-Baradei said the weapons inspectors had had "very good discussions" with Mr Blair and Mr Straw on how the Iraqi issue could be resolved through peaceful means.

"That continues to be our aim," he said.

Mr Blix said the Iraqi regime had provided prompt access to the facilities which the inspectors wanted to examine. But full cooperation had not been forthcoming.

He said: "What has not worked is for the Iraqi side either to present prohibited items for destruction or present evidence that they are finished. On this point, we do not feel that we have had the response we should."

Mr Blix said the inspectors also wanted progress from the Iraqis on allowing U2 spy plane flights over the country and on interviews with scientists at which official minders were not present.

He said: "We hope that at this late hour they will come to a positive response. If they do not do that, then our reports next Friday will not be what we would like them to be."

Mr Blix reiterated that the inspectors wanted to see Iraq disarmed via the inspections process.

He said: "That is the method we stand for and we would like to obtain that."

At this morning's cabinet meeting, Mr Blair told ministers that President Saddam had to begin cooperating with the weapons inspectors if he wanted to avoid war. And he said it was not enough simply to bring in more inspectors, as the French have been suggesting.

"More inspectors by themselves won't resolve the issue," Mr Blair's official spokesman said. "The key question is not what the inspectors find, but whether Saddam helps them to find his weapons of mass destruction."

Today the defence secretary, Geoff Hoon, will make another announcement on the deployment of further troops to the Gulf region, including dozens of RAF aircraft and another 6,000 personnel, bringing the UK's overall contribution to almost 40,000.

After meeting Mr Blair and Mr Straw, Mr Blix was flying on to Vienna, where his agency is based, before going on to Baghdad, while Mr el-Baradei was flying on to Cyprus to meet his own officials before also returning to the Iraqi capital.

· Two British MEPs today returned from Iraq demanding weapons inspectors are given more time.

Plaid Cymru MEPs Jill Evans and Eurig Wyn held talks with representatives of the UN weapons inspections team during a European parliament trip to Baghdad.

They said the Britain and the US risked undermining the inspectors' work by putting them under pressure. In a statement, the Welsh MEPs said: "There is clear evidence that they need more time to complete their inquiries.

"Over 500 sites have been inspected to date and more visits are planned. The inspections programme is going to plan and it is clear that the work should not be thwarted by outside political influences.

"We call on the British government not to undermine the work of the inspectors by bringing undue pressure on them to produce premature results."

The MEPs also called on the Iraqi government to co-operate "fully and proactively".

"The importance of allowing the weapons inspectors sufficient time is paramount to avoid war and the ensuing death of half a million people," they added.